Photonic scanning receiver using an electrically tuned fiber Bragg grating

Abstract

A 5-cm-long electrically tuned fiber Bragg grating is used to filter a microwave signal on an optical carrier at 1.55 mum. A chirped distributed-feedback structure is employed, with a transmission bandwidth of 54 MHz and relative optical carrier rejection of >30 dB for rf frequencies >2 GHz. The rapid monotonic sweep of the Bragg wavelength is translated into a fast-frequency sweep for rf analysis.

Tunable Photonic Microwave Generation Based on a Novel Dual-Polarization Fiber Laser Cavity

“…The internal electrodes of the THF enables tuning of the Bragg wavelength of the DFB grating [25] as well as tuning of the beat frequency generated. The energy deposited by the voltage applied to one of the electrodes heats it and causes it to expand.…”

Instantaneous microwave frequency measurement with improved measurement range and resolution based on a polarization modulator

“…Usually, the frequency of the intercepted radar signal can vary from hundreds of MHz to tens of GHz. As the conventional electronic techniques for microwave frequency measurement are thought to be slow, limited in bandwidth and vulnerable to electromagnetic interference (EMI), numerous photonic approaches to realizing microwave frequency measurement have been proposed and demonstrated [2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

“…In [2][3][4], photonic scanning receivers were proposed for the microwave frequency measurement. In [2], a Fabry-Perot (F-P) etalon-based temporal scanning receiver system was proposed with a scanning range of 40 GHz and a resolution of 90 MHz.…”

“…In [2], a Fabry-Perot (F-P) etalon-based temporal scanning receiver system was proposed with a scanning range of 40 GHz and a resolution of 90 MHz. An electrically tunable fiber Bragg grating (FBG) and a thermally tunable echelle diffractive grating were used in [3] and [4] to realize microwave frequency measurement. Although the scanning receivers can be used to measure multiple microwave frequencies, the scanning time of this method is usually long and thus, the measurement is not instantaneous.…”

Instantaneous high-resolution multiple-frequency measurement system based on frequency-to-time mapping technique

“…However, these methods are not applicable in the important realistic scenarios where the microwave signal comprises multiple frequencies or the signal is embedded in a spectrally cluttered environment. Techniques to enable multiple-frequency measurement have been reported [7][8][9][10][11][12][13]; however, most of the previous multiple-frequency measurement schemes require a tunable laser or a scanning optical filter [7][8][9], which make the system latency a serious issue; or otherwise, a high-speed photodetector (PD) and high-speed fast Fourier transformation are necessary [10]. Scanning receivers exploiting the SBS effect have been proposed [8,9], which can measure multiple RF frequencies; however, the system latency is dependent on the sweeping speed of the local oscillator, which can be of the orders of milliseconds.…”